1. Field of the Invention
The present invention relates to a map-information display system used by a movable body for retrieving map information from a recording medium and displaying the retrieved information.
2. Description of Related Art
A map-information display apparatus for retrieving map information of a certain area and displaying the information is disclosed in Japanese Patent Laid-open No. Hei 7-73396. The map-information display apparatus retrieves map information of an area required by the operator and displays the information.
When retrieving, for example, map information regarding a route which is specified by the operator and which includes a detour; the apparatus retrieves map information in the vicinity of the detour. However, the apparatus also retrieves unnecessary map information encircled by the detour. This inevitably causes a large amount of retrieved map information. In addition, if the amount of retrieved map information exceeds the capacity of a storage medium employed in the map-information display apparatus, an inability to accommodate the retrieved map information in the storage medium can occur.